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Holger Sudhoff

Publications and source records attributed to Holger Sudhoff.

At least 19 recordsLinked to original sources
PubMed2007

Tracing of gastric reflux into the middle ear in a mongolian gerbil model.

OBJECTIVES: The purpose of this study was to trace induced gastric reflux and to examine whether it reaches the middle ear in a Mongolian gerbil model. BACKGROUND: Otitis media with effusion is the most frequent middle ear disease in childhood. Gastroesophageal reflux is suspected to be a possible factor in its pathogenesis. METHODS: Seventeen Mongolian gerbils were assigned to three groups: the control (phosphate-buffered saline application to the lower esophageal sphincter) and two experimental groups (Aquo-Trinitrosan [Merck, Darmstadt, Germany] application to the lower esophageal sphincter, low gastric pressure and Aquo-Trinitrosan application, higher gastric pressure). We injected Chinese ink into the stomach to trace the path of a potential gastroesophageal reflux in all three groups. The traces of ink were investigated by ear and larynx endoscopy and histology. RESULTS: There were no signs of gastroesophageal reflux based on the data obtained from the control group. In animals with traceable laryngeal reflux, the ink was also shown to advance through the eustachian tube and reach the middle ear. In addition, we found that when reflux reaches the middle ear on one side, it also reaches the contralateral middle ear in most cases. CONCLUSION: Gastroesophageal reflux induced by relaxation of the lower esophageal sphincter was shown to reach the middle ear in our Mongolian gerbil model. These results support recent hypotheses linking gastroesophageal reflux to the development of otitis media with effusion.

Animals↗
PubMed2006

Low prevalence of transfusion transmitted virus (TTV)-like DNA sequences in cystadenolymphoma and pleomorphic adenoma of the salivary glands.

Titers of transfusion transmitted virus (TTV)-like DNA in saliva samples have been reported 100-1,000 times higher than those of the corresponding sera, suggesting viral transmission by saliva droplets. The present study was conducted to determine whether TTV-like DNA sequence elements play a role in the pathogenesis of cystadenolymphoma or pleomorphic adenoma and if the parotid or the submandibular gland is a major source of TTV persistence. Sixty-two archival salivary gland samples (16 cystadenolymphomas, 13 pleomorphic adenomas, and 33 controls) and 23 corresponding saliva samples were examined using a polymerase chain reaction (PCR) for TTV DNA. All PCR products that displayed DNA bands were sequenced. Leder's stain and immunohistochemistry (anti-CD8, anti-CD20, anti-CD45R0, anti-CD68, and anti-Ki67/MiB1) were applied to detect possible changes associated with findings of TTV-like DNA sequences. Tissue displayed TTV-like DNA sequences in 8.1% (5/62; saliva: 47.8%, 11/23). Tissue that contained TTV-like DNA sequences was histologically indistinguishable from samples lacking such DNA. TTV appears to be only a bystander in cystadenolymphoma, pleomorphic adenoma, and other salivary gland affections. Neither of the glands seems to be a major source of TTV persistence.

Adenolymphoma↗
PubMed2005

A computer-based approach to assess the perception of composite odour intensity: a step towards automated olfactometry calibration.

The 2004 Nobel Prize in Physiology or Medicine laureates, Richard Axel and Linda Buck, have made smell a less enigmatic sense to study. In clinical routine, olfactory function is assessed using defined concentrations of a single defined substance, a setting which is uncommon in daily life. The present study was therefore conducted to evaluate the applicability of composite odours. Air was contaminated with different quantities of cyclohexanol, cyclohexanone and cyclohexane to generate 73 gas mixtures (one component: n = 21, two components: n = 40, three components: n = 12). The intensity of perception was estimated for each mixture by an average of 60.3 healthy individuals (4,403 assessments). An artificial neural network (ANN) was trained and validated using the contaminants' concentrations with the corresponding estimated intensities. The inter-rater variability was low, as 75.7% of the assessments did not exceed a difference beyond 0.5 from the corresponding median (considered correct predictions). The ANN correctly estimated 78.1% of the gas mixtures, and in terms of the regression task the ANN demonstrated a sufficient prediction performance (Pearson's correlation coefficient r = 0.883; R(2) = 0.757) and outperformed linear regression (r = 0.770; R(2) = 0.667). Evaluating extra ANNs for gas mixtures comprising one, two or three components, the predictive power did not decrease when complexity increased. The aforementioned results reflect nonlinearity in human perception. ANN technology helps simulate human perception of composite odour intensity which may be applicable to olfactometry calibration and systems biological mathematical modelling. The use of composite odours may represent real-life problems more adequately than single substances.

Adult↗
PubMed2005

Role of mast cells in otitis media.

BACKGROUND: New pathophysiologic concepts are needed to explain the clinically observed connection between the allergic diathesis and otitis media. Although mast cells, unlike lymphocytes, are common in the normal middle ear mucosa, their potential role in innate immunity of the middle ear and in the expression of inflammatory responses in that space to bacterial challenge, as opposed to allergy, has received relatively little attention. OBJECTIVE: In the current study, we examine the contributions of mast cells to the pathogenesis of bacterially induced inflammation in the middle ear and thus to otitis media. METHODS: Wild-type mice, mast cell-deficient mice, and mast cell-deficient mice whose mast cell populations were restored by transplantation of bone marrow-derived mast cells were challenged by using models of bacterial and allergic middle ear inflammation. RESULTS: Our results indicate that mast cells account for a substantial proportion of the innate immune response to bacteria in the middle ear. CONCLUSION: This mechanism may link responses to allergy and infection in the middle ear mucosa, and thus the mast cell may be a critical control element in the pathogenesis of otitis media.

Animals↗
PubMed2005

Rare tumors of the internal auditory canal.

The study was performed to identify the incidence and histology of rare tumors with growth restricted to the internal auditory canal (IAC) that are different from vestibular schwannoma (VS). Furthermore, the question was addressed whether a preoperative diagnosis would be possible in these cases. A series of 351 patients that were operated on for IAC tumors through a transtemporal or translabyrinthine approach was investigated retrospectively. Cases with a tumor entity other than VS were analyzed for symptoms, radiological diagnosis, intraoperative findings and postoperative histolopatology to determine if a differential diagnosis to the common VS can be established prior to surgery. In 15 out of 351 cases (4.3%), uncommon processes of the IAC were determined by histology (6 lipomas, 3 hemangiomas, 2 neurofibromas, 2 menigiomas, 1 facial neuroma and 1 case of bilateral malignant lymphoma). The symptoms and the clinical manifestations were typical for patients with VS so that a preoperative differential diagnosis was not possible in the majority of cases. An analysis of the operation reports revealed that in 10 out of the 15 cases the surgeon suspected an unusual tumor of the IAC during surgery. The results of the present investigation suggest that rare lesions of the IAC can be expected in less than 5% of the cases and that preoperative diagnosis of rare IAC tumors is difficult. Intraoperative findings such as adhesion to cranial nerves and consistency of the tumor often indicate unusual processes, but histological analysis of the removed tissue is essential for the definite diagnosis.

Ear Neoplasms↗
PubMed2005

Cytokeratin expression pattern in congenital and acquired pediatric cholesteatoma.

Pediatric cholesteatoma can be classified as congenital or acquired based on clinical criteria. We studied the expression patterns of five distinctive cytokeratins in both types of cholesteatoma in order to improve understanding of their pathogenesis and origin. A comparable expression pattern for CK10, CK14, CK18, CK19 and 34betaE12 antigens was found in the matrix of congenital and acquired pediatric cholesteatoma. Our results demonstrate that congenital and acquired pediatric cholesteatoma exhibit an identical cytokeratin distribution pattern, suggesting that they share a common origin. Therefore, it seems possible that a portion of the so-called "acquired" cholesteatoma may actually originate from advanced congenital cholesteatoma with secondary destruction of the tympanic membrane in the pediatric patient population.

Child↗
PubMed2005

Transtympanic corticoid therapy for acute profound hearing loss.

The prognosis of idiopathic sudden hearing loss depends on its severity; acute complete deafness, for example, has a particularly bad prognosis. The treatment of acute deafness is based on a systemic application of corticosteroids. Corticoid concentrations in the cochlea are higher after transtympanic application in comparison to systemic application. We therefore investigated whether an additional transtympanic corticoid therapy gives an advantage over systemic standard therapy. We report on 27 patients with sudden idiopathic profound hearing loss or deafness who were treated in the Department of Otorhinolaryngology, University of Essen, Germany. Fourteen patients were treated with a rheologic infusion therapy with systemic prednisolone. Thirteen patients were treated additionally with methylprednisolone (Urbason) transtympanically through a ventilation tube. In the first group of patients who were treated with infusion therapy and corticoids systemically, three patients had good recovery of hearing. Another five patients had a partial recovery of hearing. The average hearing gain from 0.5-4 kHz was 15 dB. In the group of patients who were treated additionally with local corticoids, two patients reported a good recovery of hearing and another two patients only had a partial recovery of hearing. The average hearing gain in the above-mentioned frequency range was 11 dB. In our patients the additional transtympanic application of corticoids did not result in a significantly improved recovery of hearing in comparison to the patients treated with the standard therapy alone.

Acute Disease↗
PubMed2005

Study of osteointegration of a titanium prosthesis to the stapes: observations on an accidentally extracted stapes.

BACKGROUND: Titanium is a well-established implant material, and its use in ossicular chain reconstruction during middle ear surgery is increasing. HYPOTHESIS: Bony fixation of titanium prostheses has to be considered using this material. Contact with bony structures of the middle ear may result in immobilization. In revision procedures, there is a potential risk of damaging or extracting adherent structures such as the stapes. METHODS: This is a case report of an accidentally extracted stapes resulting from bony fixation of a titanium prosthesis in revision tympanoplasty. The surgical specimen was examined by microscopy, histology, and scanning electron microscopy. Energy dispersive x-ray analysis was used to confirm the elemental composition of the extracted stapes and the titanium prosthesis. RESULTS: The prosthesis showed good biocompatibility at the implantation site, with signs of bone resorption of the stapes suprastructure. However, bony fixation of the undersurface of the prosthesis foot to the stapes footplate was confirmed by ultrastructural analysis. CONCLUSION: In revision tympanoplasty, bony fixation of the titanium prosthesis should be considered.

Audiometry, Pure-Tone↗
PubMed2004

Creating artificial perichondrium by polymer complex membrane macroencapsulation: immune protection and stabilization of subcutaneously transplanted tissue-engineered cartilage.

Functional organ or tissue failure is one of the most frequent, devastating and costly problems in modern health care. The field of tissue engineering has tremendous potential for developing new functional tissue. In reconstructive surgery, cartilage engineering could be a serious alternative to the established method of autologous cartilage transplantation. Recent studies demonstrate cartilage engineering by subcutaneous implantation of chondrocyte-seeded PGA/PLA-fibrin glue scaffolds in the backs of nude mice. In both autologous cartilage transplantation and cartilage engineering, the host immune response affects transplant integrity and cartilage morphology to an unforeseeable extent. To investigate whether polyelectrolyte complex (PEC) membranes can prevent rejection of cartilage transplants without neglecting tissue metabolism, tissue-engineered cartilage encapsulated with a PEC membrane was subcutaneously implanted in the backs of nude mice. Non-encapsulated tissue-engineered cartilage was used for the control group. Histochemistry and scanning electron microscopy were performed 4 and 12 weeks after implantation. There was no interaction between the host and the implant with an intact PEC membrane. With protection by PEC encapsulation, implanted tissue-engineered cartilage showed no signs of degeneration and had a significantly weaker cellular immune response than without it. Thus, PEC membrane encapsulation appears to be a novel approach for protecting cartilage implants from host immune response after autologous transplantation.

Animals↗
PubMed2004

The 'subsequent artificial neural network' (SANN) approach might bring more classificatory power to ANN-based DNA microarray analyses.

MOTIVATION: Human decisions often proceed in two steps. Initially those most preferred are chosen followed by a subsequent choice of these preferences. Applying one artificial neural network (ANN), a classification is limited to the preselection process. The final categorization is only possible by a subsequent ANN that distinguishes the pre-chosen classes. Existing strategies using coupled ANNs are discussed and a new approach particularly suited for multiclass classification problems is introduced ('Subsequent ANN', SANN). RESULTS: Evaluating a simulated data base comprising 3 classes, classification results of SANN were obviously superior to those achieved by ANN. To evaluate a real-world data base the microarray benchmark GCM (14 classes) was chosen. The ANN results reached 72%, comparable to previous results. Using SANN, up to 81% of the tumors were correctly classified. AVAILABILITY: Programs used in this work and numerical results are available upon request.

Algorithms↗
PubMed2003

Etiopathogenesis of cholesteatoma.

Cholesteatoma is a destructive lesion of the temporal bone that gradually expands and causes complications by erosion of the adjacent bony structures. Bone resorption can result in destruction of the ossicular chain and otic capsule with consecutive hearing loss, vestibular dysfunction, facial paralysis and intracranial complications. Surgery is the only treatment of choice. The etiopathogenesis of cholesteatoma, however, is still controversial. This review was designed to understand the reasons for these disparities and to reduce or eliminate them. Future studies focused on developmental, epidemiological, hormonal and genetic factors as well as on treatment are likely to contribute to further understanding of cholesteatoma pathogenesis.

Antigens, Differentiation↗
PubMed2003

Inflammation of embryonic connective tissue in the middle ear spaces.

OBJECTIVE: Persistent embryonic connective tissue has been considered to be a cause of chronic otitis media with effusion in neonates and of cholesteatoma in later life. As part of a study of pneumatization and resorption of embryonic connective tissue from the middle ear of pre- and postnatal infants, inflammatory processes of variable extents have been observed within the embryonic connective tissue. The aim of the present study was to characterize this inflammation and to detect patterns in its presence and distribution. MATERIAL AND METHODS: Twenty fetal temporal bones obtained at 4-8 months of development and 31 temporal bones from children who died of sudden infant death syndrome aged < 1 year were studied to assess the inflammation within the middle ear cleft and specifically in the embryonic connective tissue. RESULTS: Sixteen of 27 (59.3%) pre- and 10/31 (32.2%) postnatal specimens displayed a non-specific inflammatory lymphocytic infiltration without signs of bacterial infection or the presence of or reaction to amniotic contents. Eleven of 27 prenatal temporal bones (40.7%) and 16/31 (51.6%) postnatal specimens showed no evidence of histologic middle ear inflammation. The presence or absence of inflammation was independent of age. CONCLUSION: Our observations indicate resorption of the embryonic connective tissue with individual variations indicating that genetic factors are responsible for the development of the middle ear spaces during the phases of development studied.

Acute Disease↗
PubMed2003

Osteoclast stimulating and differentiating factors in human cholesteatoma.

OBJECTIVES: To investigate the expression of osteoclast-activating and differentiating factors and to study the occurrence of osteoclast precursor cells and osteoclasts in acquired human cholesteatoma tissue. METHODS: We examined 21 cholesteatoma samples versus 18 normal auditory canal skin specimens for the expression of osteoprotegerin ligand (OPGL), osteoprotegerin (OPG), and macrophage-colony stimulating factor (M-CSF) using reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. Immunohistochemistry and computer-assisted microscopy using markers CD4, CD11a, CD11b, CD14, CD51, CD68, and TRAP obtained the detection of osteoclast cell lineage. RESULTS: An increased expression of the investigated cytokines M-CSF, OPG, and OPGL was demonstrated by immunohistochemistry and RT-PCR in cholesteatoma tissue compared with normal external meatal skin. Several CD4-positive cells exhibited a co-expression for OPGL within the perimatrix of cholesteatoma. The presence of osteoclast precursor cells was confirmed in all samples of cholesteatoma tissue. CONCLUSIONS: This study reveals that the number of osteoclast precursor cells is markedly increased in the perimatrix of cholesteatoma tissue. Our results support a concept described for inflammatory arthritis: the inflammation related to cholesteatoma induces bone resorption by release of OPGL from activated T-cells and triggers osteoclastogenesis. This could be a major target for drugs to inhibit osteoclast formation and bone resorption and may be an adjunct in cholesteatoma management.

Antigens, CD↗
PubMed2003

Evidence against neonatal aspiration of keratinizing epithelium as a cause of congenital cholesteatoma.

OBJECTIVES/HYPOTHESIS: It has been suggested that congenital cholesteatoma may be caused by perinatal aspiration of squamous epithelium. STUDY DESIGN: Microscopic study of fetal temporal bones. METHODS: Thirty-one temporal bones from infants who died of sudden infant death syndrome before 1 year of age and 27 temporal bones obtained from preterm fetal deaths aged 4 to 8 months of fetal development were studied to assess signs of aspiration of squamous epithelium in the middle ear. RESULTS: None of the prenatal or postnatal temporal bones showed keratinizing epithelial cells or lanugo. A certain number of specimens displayed a nonspecific inflammatory lymphocytic infiltration. CONCLUSION: The data in the present study do not support the theory of amniotic fluid and squamous epithelial aspiration as an origin of congenital cholesteatoma.

Cell Movement↗
PubMed2003

A murine model of cholesteatoma-induced bone resorption using autologous dermal implantation.

OBJECTIVE: To investigate a novel murine model for dermal implant-induced osteolysis analogous to bone resorption observed in middle ear cholesteatoma. STUDY DESIGN: Animal experiment. METHODS: We placed autologous dermal implants on the surface of mouse calvaria. The calvaria were examined at days 1, 3, 5, 7, and 14 after implantation by histological study and tartrate-resistant acid phosphatase immunohistochemical processing to detect osteoclasts. RESULTS: Dermal implants showed a significantly increased osteoclast density compared with control samples. The dermal implant tissue remained viable and produced a robust, localized inflammatory osteolytic response on the adjacent calvarial surface. Osteoclasts were predominantly found on the surface of the calvarium with the greatest osteoclast density seen at 5 to 7 days after implantation. CONCLUSION: The mouse model is expected to be a useful tool for investigating the pathogenesis of localized inflammatory bone resorption related to cholesteatoma.

Animals↗